Electrolytic capacitor



May 9, 1944.

F. s. DU NLEAVEY ELECTROLYTIC CAPACITOR Filed Aug. 14, 1959 INVENTQR.

BY y

' ATTORNEY Patented Ma 9,1944 p 2,348,284

UNITED STATES PATENT OFFICE ELECTROLYTIC cAPacrron Frank s. Dunleavey,Fort Wayne, Ind., assiznor, by meme assignments, The M rtian: Com- 1may, Fort Wayne, Ind, ncorporation of Delav attra ts-awed 93.9; iS eriallN'o.'290,:0Q4

The present invention relates to electro ic tubeto the; passage of vaporor liquid phases capacitors or condensers and more particularly of the ee t y e is gr atl decreased and conse-. to a novel tube or containertherefor and in the quently the .loss of these phases under actual novelmeans and method of forming or fabricatop rating or service conditionsis pr v 1 ing such tube or container for housing the ca- 5 materiallyreducedpacitor rolls of a dry electrolytic capacitor. Another obleet 0fthe P e t in ention is to One serious objection to the prior commercialpr v e a n v l inner hher for a tube or contypes of paper tube or caseis ;that-.;thei'ionic h an e ect ytic condenser. conduction of freeinorganic ions hash suflistructed fabricated and arranged as to formcient to cause corrosive eflects on the capacitor int nu m h t liningforming a P rrier roll, and the vapor and liquid phases 0: the else; inet the nhg e of a y morsemc ions trolyte provide leakage pathsthroughthetub'e fi d-P odu e o ive e ects on the such that theinsulating value of the tube-wall c Mater." In its preferred form, isnot sufflcient to give trouble-freeservicefM "the v ti!) p s fabrlcetmgthe l er electrical device on which it is-emp1oyed., 'rhese. emin tlonscellulose a e ate film, aludissociated ions in the tube wan are metoimov el um. {ahea ond p per suitably afli ed. with to the anode orcathode and react with the ele the ulo e film and metal foil securedtrode material, with the degree or attack dehe eeq e edheslve to whi hasbeen pendent upon the ionic conductivityv and degree 5 h hl l y inertcarbon blach which inof impermeability of the tube. This dangerous e sthe iscosity of the adhesive and the ionic conductivity and it corrosiveeffect upon w tn s Q th in t. and the carbon the electrodes and tabs issuch as temateriauyl n e m hs break up the paths oi the reduce the lifeof the capacitor. im :5 s to materially eese their length Anotherserious objection has'been that inthe T -3 -t r migration andconducprior typef paper tubes or containers f r; 1 c tlVltY-, Thethermoplastic adhesive loaded with trolytic capacitors considerabledifliculty has. been experienced in that the adhesive used-to K 95?acetate m 1n eddltwn to the reeal the edges has-been water ductionmf the101110 Conducpion Of Such consequently these seams are readily opened byv materially teduces the mmsture P i y sources of water or other solventvapors or liqm' uids from the interior orv exterior of the tube.objects, advantages f p bl ties Thus the permeability of the tube tothe'pas- 31 apparent m he description or disclosage of vapor or liquidphases of the electrolyte Sure mule are inherent in he deused in dryelectrolytic capacitor rolls is con "9 v/ siderably increased and theloss Oftheselliquid 85 r d w or vapor phases under service conditionsthrough 1-,-

t, 1 1S a View 111 l ohtal cross section the tube wall or otherwise,greatly shortens the hmugh an electroltflc capaclto! employing thecapacitors life. i a novel tube or container structure.

A t n further objection to these .pflo/r ftybgs/ Fig. 2 18 an enlargedview in horizontal cross of paper tubes has been the-cost of manuiactu e40 sectwn through the tube or co tainer. in that an vendeawn. topmvideaiaddltiovm F g. 3 IS a fragmentary view in horizontal cross barrier ors a n liquidv and vapor section of a inrther enlargement showing thedeha' i t 'ele'ctjoly te fie scapingfrom e unit, I tails of the innerliner.

an inner seal or wra4'i1oiai7around the roll has been 3 Referring moreparticularly to the distlosule provided andv the;nds...bf thiS wrapperwere inthe drawing and the embodiment selected to 'neces-Sity. se-alvdiwithilwavx additional illustrate the invention, the electrolyticconwrapper andpouringnecessitated additional denser comprises a tube orcontainer I housing erations and material due mean inherent or/enclosmga conventional capacitor roll havciency in the prior tubes, but even so,the service mg t and leads 3 and 4 tending to the life of the capacitorsso cased has been relativeextenor- 1y h w The disclosed embodiment oftube or con- It i therefore, an object of the present inventainercomprises a tubular member or main body tion to provide a tube or casefor an electrolyti portion 5 formed of spirally wound layers orcondenser in which the ionic conduction or Plies f paper, pr f rably agood grade of kraft migration'of any inorganic ions is prevented orPaper i the SeemS'Of al eo vo utions reduced t minimum, thereby greatlyprolongadhesively secured togethef'in e/ manner that ing the life of thecapacitor and giving optimum the Seams are out Of alignment g Theefiiciency nd performance, body portion is of suflicient thickness andIcon- A further object is the provision of a 'novel Struction to providea Permanent casing}, a

carbon black'clogs the minute openings in the type'of container in whichpermeability or {71s give the tub the rigidity/ required, *a d furtherrating of the device and other suitable identification or decoration asmay be deemed necessary or desirable. 4

In the preferred form shown, the inner lining 6 consists of three pliesof material arranged in a novel manner to secure a moisture-proof andvapor-proof barrier having high impermeability to the migration of ions.This inner liner is more clearly shown in Figures 2 and 3 wherein theplies comprise a .sheet or film of cellulose acetate or any othersuitable cellulose derivative 8, laminated to a metal foil 9, the latterbeing secured to a sheet or lamina of bond paper In by means of asuitable adhesive. In laminating the foil to the bond paperexcellentresults have been secured by the use of a casein latex or areasonably neutral cement or adhesive of thecasein latex type. Inlaminating the cellulose acetate to foil-paper combination, excellentresults have been secured by the use of a thermothe capacitor roll l8and the assembly of the tabs to the lead wires.

Although the disclosure has been directed more particularly tocondensers or capacitors, it will be evident to those skilled in the artthat the invention is applicable to other uses and constructions such aselectrical components including resistors, inductors, etc.

Having thus disclosed the invention, I claim:

1. A tubular article forenclosing an electrolytic capacitor comprisingan outer strengthening layer, and having an inner liner comprising threelayers of material one of said layers being plastic resin type,black-pigmented adhesive.

These three layers or laminae provide a liquidproof andvapor-prooflining against the penetration of electrolyte liquid orvapors through the tube wall, and reduce the ionic conductivity to aminimum.

In the fabrication of the, liner, I have secured composed of a cellulosederivative, another layer being composed of metal foil and a third layercomposed of paper, and an adhesive located between said cellulosederivative and said metal foil layers. I

2. A tubular article for enclosing an electrolytic capacitor comprisingan outer strengthening layer, and having an inner liner comprising threelayers of material one of said layers being composed of celluloseacetate, another layer being composed of metal foil and a third layercomposed of paper, and an adhesive located between said celluloseacetate and said metal foil layers. 3. A tubular article for enclosingan electrolytic capacitor comprising an outer strengthenexcellentresults .by laminating a metal foil 9 such as aluminum of approximately.0003 to.

.0005 inch thickness, to abond paper l0 of suitable weight. This isaccomplished by means of a suitable casein latex adhesive well known inthe art of'laminating paper .to aluminum or other metal foils. Thecellulose acetate film or sheet 8 is then secured to the face of thealumi-fi num foil 9 by means of a, thermoplastic cement,

or adhesive H to which has been added chemi-' cally inert carbon black.I have securedex cellent results by using a lacquer type ofthermoplastic. This cellulose acetatefihn or sheet is laminae so thatthe margin portion l2 of this sheet may be reversely folded over at I3onto the bond paper l0 and thereby make a tight seal.

In the process of fabricating the tube, the inner lining material islaid film face down on a winding mandrel and the next ply or coil of thelining material is lapped over and engages the reversely turned portionof the first piece or coil as illustrated in Fig. 2. The edges of thelaminated lining 6 are bonded by an adhesive or suitable solvent such asacetone or other solvents adaptable to cellulose derivatives. By thusbonding or seaming the adjacent plies or convolutions of paper [0, foil9 and cellulose acetate minimized, and by coating the entire innersurface of the liner with such adhesive, excellent results both as toprevention of ionic conductivity and liquid and vapor-proofness aresecured.- The tube is sealed on the ends with a suitablepotting compoundwhich closes the ends and seals of suflicient width as to overhang thefoil-paper ing layer, and having an inner liner comprising three layersof material, one of said layers being composed-of a cellulosederivative, another layer being composed of metal foil and a thirdlayer' composed of paper, and an adhesive located between said cellulosederivative and said metal foil layers, said adhesive containing carbonblack particles.

4. A tubular article for enclosing an electrolytic capacitor comprisingan outer strengthening layer, and having an inner liner comprising threelayers of material one of said layers being I composed of a cellulosederivative, another layer being composed of metal foil and a third layercomposed of, paper, and an adhesive located between said cellulosederivative and said metal foil layers, said adhesive containingchemically inert conducting particles.

5. A casing or'housing for enclosing an electrolytic capacitorcomprising an outer strengthening layer, and having an'inner liner,comprising a plurality of layers of material one of said layers beingcomposed of a cellulose derivative, another layer being composed ofmetal foil and a third layer composed of paper, and; an adhesive locatedbetween said cellulose de-,

rivative and said metal foil layers, said adhesive containing carbonblack particles.

6. A casing or housing for enclosing an electrolytic capacitorcomprising an outer strength ening layer, and having an inner linercomprising'a plurality of layerg, of material one of said layers beingcomposed of a cellulose derivative, another layer being composed ofmetal foil and a third layer composed of paper, and an adhesive locatedbetween said cellulose derivative and said metal foil layers, saidadhesive containing chemically inert conducting particles.

7. As an article of manufacture, a container comprising a rigid outersupporting tube and a liner comprising a paper backing member, avapor-proof metal foil laminated to said backing member, a.substantially inert liquid-proof film and an adhesive adhering said filmto said foil, said adhesive containing chemically inert particles.

FRANK I S.- DUNLEAVEY.

